I feel for you.
I finally put my boys in daycare. I should have done it sooner. I have no words of wisdom. I still have anxiety just reading this thread. Anxiety about how long I waited, anxiety about the thought of telling your wife.
I will say run it past your lawyer.
My xah went to rehab shortly after I put the kids in daycare and filed for divorce. I kept the kids in daycare when he came home. He received the divorce papers while he was in rehab and by the time he got home - he had a lawyer of his own.
His laywer told him to go get the kids every day and bring them home. Without legal custody and/or other documents in place - there was really nothing I could have done to prevent that. His case for custody would be infinitely better if they were home with him and him being out of rehab and 'sober' with no history of abuse - there wouldn't have been a lot I could have been done about it. He had been home with them since the twins were born. I did speak with my lawyer. Judges here like to keep the 'status quo' for kids unless it is proven to be detrimental to the kids. So his lawyer wanted the kids home with him, mine wanted them to stay in daycare. I of course no longer trusted him to provide good care so I wanted them in daycare.
Xah's sister, thankfully, talked him out of that. He didn't remain sober long so he quit barking up that tree. I think is primary purpose was to scare/manipulate me anyway - which, to be honest, worked for a few months.